libavfilter/af_resample.c

   1 /*
   2  *
   3  * This file is part of Libav.
   4  *
   5  * Libav is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2.1 of the License, or (at your option) any later version.
   9  *
  10  * Libav is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General Public
  16  * License along with Libav; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  18  */
  19
  20 /**
  21  * @file
  22  * sample format and channel layout conversion audio filter
  23  */
  24
  25 #include "libavutil/avassert.h"
  26 #include "libavutil/avstring.h"
  27 #include "libavutil/common.h"
  28 #include "libavutil/dict.h"
  29 #include "libavutil/mathematics.h"
  30 #include "libavutil/opt.h"
  31
  32 #include "libavresample/avresample.h"
  33
  34 #include "audio.h"
  35 #include "avfilter.h"
  36 #include "formats.h"
  37 #include "internal.h"
  38
  39 typedef struct ResampleContext {
  40     const AVClass *class;
  41     AVAudioResampleContext *avr;
  42     AVDictionary *options;
  43
  44     int64_t next_pts;
  45
  46     /* set by filter_frame() to signal an output frame to request_frame() */
  47     int got_output;
  48 } ResampleContext;
  49
  50 static av_cold int init(AVFilterContext *ctx, AVDictionary **opts)
  51 {
  52     ResampleContext *s = ctx->priv;
  53     const AVClass *avr_class = avresample_get_class();
  54     AVDictionaryEntry *e = NULL;
  55
  56     while ((e = av_dict_get(*opts, "", e, AV_DICT_IGNORE_SUFFIX))) {
  57         if (av_opt_find(&avr_class, e->key, NULL, 0,
  58                         AV_OPT_SEARCH_FAKE_OBJ | AV_OPT_SEARCH_CHILDREN))
  59             av_dict_set(&s->options, e->key, e->value, 0);
  60     }
  61
  62     e = NULL;
  63     while ((e = av_dict_get(s->options, "", e, AV_DICT_IGNORE_SUFFIX)))
  64         av_dict_set(opts, e->key, NULL, 0);
  65
  66     /* do not allow the user to override basic format options */
  67     av_dict_set(&s->options,  "in_channel_layout", NULL, 0);
  68     av_dict_set(&s->options, "out_channel_layout", NULL, 0);
  69     av_dict_set(&s->options,  "in_sample_fmt",     NULL, 0);
  70     av_dict_set(&s->options, "out_sample_fmt",     NULL, 0);
  71     av_dict_set(&s->options,  "in_sample_rate",    NULL, 0);
  72     av_dict_set(&s->options, "out_sample_rate",    NULL, 0);
  73
  74     return 0;
  75 }
  76
  77 static av_cold void uninit(AVFilterContext *ctx)
  78 {
  79     ResampleContext *s = ctx->priv;
  80
  81     if (s->avr) {
  82         avresample_close(s->avr);
  83         avresample_free(&s->avr);
  84     }
  85     av_dict_free(&s->options);
  86 }
  87
  88 static int query_formats(AVFilterContext *ctx)
  89 {
  90     AVFilterLink *inlink  = ctx->inputs[0];
  91     AVFilterLink *outlink = ctx->outputs[0];
  92
  93     AVFilterFormats        *in_formats      = ff_all_formats(AVMEDIA_TYPE_AUDIO);
  94     AVFilterFormats        *out_formats     = ff_all_formats(AVMEDIA_TYPE_AUDIO);
  95     AVFilterFormats        *in_samplerates  = ff_all_samplerates();
  96     AVFilterFormats        *out_samplerates = ff_all_samplerates();
  97     AVFilterChannelLayouts *in_layouts      = ff_all_channel_layouts();
  98     AVFilterChannelLayouts *out_layouts     = ff_all_channel_layouts();
  99
 100     ff_formats_ref(in_formats,  &inlink->out_formats);
 101     ff_formats_ref(out_formats, &outlink->in_formats);
 102
 103     ff_formats_ref(in_samplerates,  &inlink->out_samplerates);
 104     ff_formats_ref(out_samplerates, &outlink->in_samplerates);
 105
 106     ff_channel_layouts_ref(in_layouts,  &inlink->out_channel_layouts);
 107     ff_channel_layouts_ref(out_layouts, &outlink->in_channel_layouts);
 108
 109     return 0;
 110 }
 111
 112 static int config_output(AVFilterLink *outlink)
 113 {
 114     AVFilterContext *ctx = outlink->src;
 115     AVFilterLink *inlink = ctx->inputs[0];
 116     ResampleContext   *s = ctx->priv;
 117     char buf1[64], buf2[64];
 118     int ret;
 119
 120     if (s->avr) {
 121         avresample_close(s->avr);
 122         avresample_free(&s->avr);
 123     }
 124
 125     if (inlink->channel_layout == outlink->channel_layout &&
 126         inlink->sample_rate    == outlink->sample_rate    &&
 127         (inlink->format        == outlink->format ||
 128         (av_get_channel_layout_nb_channels(inlink->channel_layout)  == 1 &&
 129          av_get_channel_layout_nb_channels(outlink->channel_layout) == 1 &&
 130          av_get_planar_sample_fmt(inlink->format) ==
 131          av_get_planar_sample_fmt(outlink->format))))
 132         return 0;
 133
 134     if (!(s->avr = avresample_alloc_context()))
 135         return AVERROR(ENOMEM);
 136
 137     if (s->options) {
 138         AVDictionaryEntry *e = NULL;
 139         while ((e = av_dict_get(s->options, "", e, AV_DICT_IGNORE_SUFFIX)))
 140             av_log(ctx, AV_LOG_VERBOSE, "lavr option: %s=%s\n", e->key, e->value);
 141
 142         av_opt_set_dict(s->avr, &s->options);
 143     }
 144
 145     av_opt_set_int(s->avr,  "in_channel_layout", inlink ->channel_layout, 0);
 146     av_opt_set_int(s->avr, "out_channel_layout", outlink->channel_layout, 0);
 147     av_opt_set_int(s->avr,  "in_sample_fmt",     inlink ->format,         0);
 148     av_opt_set_int(s->avr, "out_sample_fmt",     outlink->format,         0);
 149     av_opt_set_int(s->avr,  "in_sample_rate",    inlink ->sample_rate,    0);
 150     av_opt_set_int(s->avr, "out_sample_rate",    outlink->sample_rate,    0);
 151
 152     if ((ret = avresample_open(s->avr)) < 0)
 153         return ret;
 154
 155     outlink->time_base = (AVRational){ 1, outlink->sample_rate };
 156     s->next_pts        = AV_NOPTS_VALUE;
 157
 158     av_get_channel_layout_string(buf1, sizeof(buf1),
 159                                  -1, inlink ->channel_layout);
 160     av_get_channel_layout_string(buf2, sizeof(buf2),
 161                                  -1, outlink->channel_layout);
 162     av_log(ctx, AV_LOG_VERBOSE,
 163            "fmt:%s srate:%d cl:%s -> fmt:%s srate:%d cl:%s\n",
 164            av_get_sample_fmt_name(inlink ->format), inlink ->sample_rate, buf1,
 165            av_get_sample_fmt_name(outlink->format), outlink->sample_rate, buf2);
 166
 167     return 0;
 168 }
 169
 170 static int request_frame(AVFilterLink *outlink)
 171 {
 172     AVFilterContext *ctx = outlink->src;
 173     ResampleContext   *s = ctx->priv;
 174     int ret = 0;
 175
 176     s->got_output = 0;
 177     while (ret >= 0 && !s->got_output)
 178         ret = ff_request_frame(ctx->inputs[0]);
 179
 180     /* flush the lavr delay buffer */
 181     if (ret == AVERROR_EOF && s->avr) {
 182         AVFrame *frame;
 183         int nb_samples = av_rescale_rnd(avresample_get_delay(s->avr),
 184                                         outlink->sample_rate,
 185                                         ctx->inputs[0]->sample_rate,
 186                                         AV_ROUND_UP);
 187
 188         if (!nb_samples)
 189             return ret;
 190
 191         frame = ff_get_audio_buffer(outlink, nb_samples);
 192         if (!frame)
 193             return AVERROR(ENOMEM);
 194
 195         ret = avresample_convert(s->avr, frame->extended_data,
 196                                  frame->linesize[0], nb_samples,
 197                                  NULL, 0, 0);
 198         if (ret <= 0) {
 199             av_frame_free(&frame);
 200             return (ret == 0) ? AVERROR_EOF : ret;
 201         }
 202
 203         frame->pts = s->next_pts;
 204         return ff_filter_frame(outlink, frame);
 205     }
 206     return ret;
 207 }
 208
 209 static int filter_frame(AVFilterLink *inlink, AVFrame *in)
 210 {
 211     AVFilterContext  *ctx = inlink->dst;
 212     ResampleContext    *s = ctx->priv;
 213     AVFilterLink *outlink = ctx->outputs[0];
 214     int ret;
 215
 216     if (s->avr) {
 217         AVFrame *out;
 218         int delay, nb_samples;
 219
 220         /* maximum possible samples lavr can output */
 221         delay      = avresample_get_delay(s->avr);
 222         nb_samples = av_rescale_rnd(in->nb_samples + delay,
 223                                     outlink->sample_rate, inlink->sample_rate,
 224                                     AV_ROUND_UP);
 225
 226         out = ff_get_audio_buffer(outlink, nb_samples);
 227         if (!out) {
 228             ret = AVERROR(ENOMEM);
 229             goto fail;
 230         }
 231
 232         ret = avresample_convert(s->avr, out->extended_data, out->linesize[0],
 233                                  nb_samples, in->extended_data, in->linesize[0],
 234                                  in->nb_samples);
 235         if (ret <= 0) {
 236             av_frame_free(&out);
 237             if (ret < 0)
 238                 goto fail;
 239         }
 240
 241         av_assert0(!avresample_available(s->avr));
 242
 243         if (s->next_pts == AV_NOPTS_VALUE) {
 244             if (in->pts == AV_NOPTS_VALUE) {
 245                 av_log(ctx, AV_LOG_WARNING, "First timestamp is missing, "
 246                        "assuming 0.\n");
 247                 s->next_pts = 0;
 248             } else
 249                 s->next_pts = av_rescale_q(in->pts, inlink->time_base,
 250                                            outlink->time_base);
 251         }
 252
 253         if (ret > 0) {
 254             out->nb_samples = ret;
 255
 256             ret = av_frame_copy_props(out, in);
 257             if (ret < 0) {
 258                 av_frame_free(&out);
 259                 goto fail;
 260             }
 261
 262             out->sample_rate = outlink->sample_rate;
 263             if (in->pts != AV_NOPTS_VALUE) {
 264                 out->pts = av_rescale_q(in->pts, inlink->time_base,
 265                                             outlink->time_base) -
 266                                av_rescale(delay, outlink->sample_rate,
 267                                           inlink->sample_rate);
 268             } else
 269                 out->pts = s->next_pts;
 270
 271             s->next_pts = out->pts + out->nb_samples;
 272
 273             ret = ff_filter_frame(outlink, out);
 274             s->got_output = 1;
 275         }
 276
 277 fail:
 278         av_frame_free(&in);
 279     } else {
 280         in->format = outlink->format;
 281         ret = ff_filter_frame(outlink, in);
 282         s->got_output = 1;
 283     }
 284
 285     return ret;
 286 }
 287
 288 static const AVClass *resample_child_class_next(const AVClass *prev)
 289 {
 290     return prev ? NULL : avresample_get_class();
 291 }
 292
 293 static void *resample_child_next(void *obj, void *prev)
 294 {
 295     ResampleContext *s = obj;
 296     return prev ? NULL : s->avr;
 297 }
 298
 299 static const AVClass resample_class = {
 300     .class_name       = "resample",
 301     .item_name        = av_default_item_name,
 302     .version          = LIBAVUTIL_VERSION_INT,
 303     .child_class_next = resample_child_class_next,
 304     .child_next       = resample_child_next,
 305 };
 306
 307 static const AVFilterPad avfilter_af_resample_inputs[] = {
 308     {
 309         .name           = "default",
 310         .type           = AVMEDIA_TYPE_AUDIO,
 311         .filter_frame   = filter_frame,
 312     },
 313     { NULL }
 314 };
 315
 316 static const AVFilterPad avfilter_af_resample_outputs[] = {
 317     {
 318         .name          = "default",
 319         .type          = AVMEDIA_TYPE_AUDIO,
 320         .config_props  = config_output,
 321         .request_frame = request_frame
 322     },
 323     { NULL }
 324 };
 325
 326 AVFilter ff_af_resample = {
 327     .name          = "resample",
 328     .description   = NULL_IF_CONFIG_SMALL("Audio resampling and conversion."),
 329     .priv_size     = sizeof(ResampleContext),
 330     .priv_class    = &resample_class,
 331
 332     .init_dict      = init,
 333     .uninit         = uninit,
 334     .query_formats  = query_formats,
 335
 336     .inputs    = avfilter_af_resample_inputs,
 337     .outputs   = avfilter_af_resample_outputs,
 338 };